1. Department of Mathematics, Comsats Institute of Information Technology, Islamabad 44000, Pakistan
2. Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000, Pakistan
3. Department of Electrical and Computer Engineering, Faculty of Engineering,King Abdulaziz University, Jeddah 21589, Saudi Arabia
4. Research Institute of Intelligent Control and System, Harbin Institute of Technology, Harbin 150080, China